Shaft-speed indicator for cream-separators and the like.



J. K. STEWART.

SHAFT SPEED INDICATOR FOR SHI -1AM SEPARATORS AND THE LIKE.

APPLICATION FILEDJAN'. 20, 1913.

Patented Jan. 6,

UNITED srarns remnant JOHN K. STEWART, or CHICAGO, ILLINoIs AssIGNoR To'srnwanrwnruraa'sa OMETER CORPORATION, or emcneo, ILLINOIS, Aconroaa'rieeror vitae-r1 SHAFT-SPEED INDICATOBTOR CREAM-SEPARAI'QIZS'XND TEE To all whom it may concern Be it known that 1, JOHN 'K. STEWART, a citizen of the United States,-residing at Chicago, in the county of Cook and State of Illinois, have invented new and useful Improvements in Shaft-Speed Indicators for Cream-Separators and the like, of which the following is a specification, reference being had to the accompanying drawings, forming. a part thereof.

The purpose of this invention is to provide an improved device for indicating the speed of a rotating shaft particularly adapted for mounting and use on the prime shaft ofa cream separator or other mechanism adaptedto have its prime shaft operated by hand at a comparatively slow speed.

'It consists in the elements and features of construction shown and described as i11- dicated in the claims. v In the drawings: Figure 1 is a front eleyfation of a'portion of a cream separator having its prime shaft equipped with a speed indicator embodying this invention.

Fig. 2is'--a section at the line, 2-2, on Fig.

1. Fig. 3 is a section at the line, 3 3, on Fig. 2.

In'the structure shown in the drawings, 1 is the prime shaft of a cream separator or like mechanism whosespeed is to be indicated. For the purpose of this invention this prime shaft is allowed to protrude from its bearings'sufliciently to carry-on the protruding end the speed indicator whose casing comprises a. bearing, 2, by which it is supported directly on the protruding end of said shaft, 1, on which therasing is pivolally' hung. '()ii the shaft within the hearing there is rigidly secured a worm gear, 4,

. which meshes with a worm shaft, 5, 'whose worm thread has a pitch of about degrees speed relatively to that of the can.

or more so that the shaft is readily rotated by the gear I and consequently at a high \Vith this coustruction the worm shaft may easily be given 'ten revolutions,toone revolution of theprime shaft. The worm shaft, 5, caran annular magnet. (3, whose rotation with the shaft produces i. rotating magnetic \iliicli'is supported rigidly within the an.

ing, as by means of four legs or arms,,8f,

Specification of Letters Patent.

Application filed January 20, 1913. Seriallt'c. 743,040.

li'el d which is modified in, form and concen Pateiirted disposedin a circle about the of the shaft, 5, at a little distance outside the circumference of the magnet; The other vice for intensifying and modifying the form of the magnetic field is a split ring, 9, having an opening,- 9, at one side, which encompasses the magnet Within the legs or arms, 8, except as to the opening, 9. which is provided for a purpose herein after explained. In the magnetic formed between the circumference the magnet and the encompassing ring, 9, and between the top or end of the magnet and the flat plate, 7, there is positioned a or flanged drag element, 10, being of else trieally conductiveand non-magnetic element, as of aluminum. This drag element is fixed upon a spindle, 11, whichis in the shaft. 3, the latter being artiall he ed to admit the spindle to its -step he therein, a second hearing for the spa being obtained on the top or front of plate 7. The apertnred ring, 9, is bianetar lic, composed of two laminae, the inner lamina being of soft iron or steel to influence the form of the magnetic field, and the outer lamina bein; of a metal r a higher coeflicieut of expansion than. its j steel, brass or copper being suitable. i is bl-llltltllllq open ring is secured at one one rigidly to one of the legs, 8, of the St 8, so that upon change of temperat re it is caused by the difference of caper. 'on of two laminae to contract or carpal-1d radially.contraclion resulting from increase of temperature because the outer lamina has the greater CO-QillCllll; of expansion.

Thechange in the width of the annular space between the magnet and the id caused by change of temperature ends to compensate for errors in the indication which would otherwise result from change of temperature affecting the electric conductivity of the drag element. 10, aetording to a principle understood. The field plate, 7, is mounted for adjustment along the of the magnet for the purpose of calibrating the instrument. The means by which it is mounted for such adjustment consists of a hub or boss, 12, which is preferably formed as a separate piece from the cage and en teriorly threaded for having the plate which is centrally apertured and threaded at its aperture screwed onto it, after which. the boss is secured to the cage at the center of I its top or front plate.-

axiallyalong the boss, .the magnet-.

' ing; 14, and be exteriorly provided" with locknut, 16, may

a drag element is visible t' chine.

' driving means casing; a magnet speed indicator comprising This boss also carries the upper bearing above mentioned for the spindle, 11. The plate, '7,is peripherally toothed; thereby becoming a spur gear; and

- on the cage there is journaled a pinion, 13, Y meshing with the peripheral teeth of said e latter to screw it plate, 7 forjrotating t 12, toward and from I The pinion shaft extends up throughitlhe top of the cage and 'may protrude through the top or cover, of the casa bur or thumb-head, 15, by which it may be rotated to adjugit the plate, 7, in

calibrating the instrume t. If desired, a be provided for, securing the plate, the casing; 14, is formed ,with a window or reading opening, 14,coinciding or registering with the opening, 9, in the field ring, 9, so that the cylind ical flange of the ough. said openings Thisdrag element exteriorly pro vided with a scale graduated in revolutions per minute, the graduations corresponding to thespeed of the shaft when the instrument is properly calibrated. Preferably, in

order to position'the casing, 14, so. that its window, 14:, shall face the operator while rotating the shaft, 1, by hand (for which a crank arm, 1%, is shown), and to prevent the natural tendency of said easi'ngto hang directly below the shaft, said casing is provided with an arm, 2*, which is stopped against a bracket, 2", which may be bolted on to the side of the standard of the ma,-

1. In combination 'with a. prime motor shaft, a speed indicator comprising speed responsive means and which is pivotally mounted on said shaft; a gear on said shaft within the casing; and from the gear to the. speed responsive means.

2. In combination with a prime motor shaft having a relatively slow speed and adapted 'to be directly rotated by hand; a a casing which is pivotally' mounted on said slowly rotating shaft; a gear on said shaft within the mounted for rotation in the casing, and means by which the gear rotates the magnet at multiplied speed,a field plate supported on the'casing for movement towardand from element positioned in the field between the magnet and the field plate; speed indicating means carried by said biased element, and means for moving the field plate toward and from the magnet forcalibrating the instrument, said means extending to thoioutside of the case for manual operation at will.

3. In combination with a prime motor shaft having a relatively slow speed and and means for adjusting 7, in adjusted-position. As usual,

. comprising journaled in pinion vto screw a casing therefor the magnet, a biased dragadapted to be manually rotated; a.speed in 'dicator comprising a casin otally mounted on said sha t; a worm car on the shaft within the casing; a worms aft .journaled in the casing meshing with and 1 driven by the worm gear;

ed on the worm-shaft for rotation thereby;

a field plate mouhted in the casing for movement toward and from the magnet-;a biased drag element positioned in the-fieldbetweenj the magnet and the field plate; indicating means carried by said biased drag element,

the fiel ward and from the magnetextending to the oufiide of the case for manual operationat W1 a speed is .to be indicated; a speed indicator a casing mounted on 'said'shaft; a driving-gear on said shaft within the casing; a driven shaft thereon for rotation therewith, and means a magnet mount- L-In combination with shaft whose which is piv plate toi which is pivotally ournaled in 'the casing;.a magnet mounted 1 for communicating multiplied'rotary move- 1 ment from said gear to said magnet-carr ing shaft; a fie casing opposite the magnet, the casing having a threaded boss and the field plate-hav threaded aperture by which it is in a scl ewed on' to the boss for so mounting it on the casing; a biased drag element positioned in the and indicating means carried by the said field plate being gear-toothed; apinion gear teeth of the field plate, and means'ex tending outside the case the fieldplate on the boss toward and from the magnet.

A speedometer comprising a casing, a

' magnet therein for rotation, and meansfor rotating it from the shaft'who'se speed is to be indicated, two field-forming-devices of magnetic ,metal mounted adjacent to -the magnet; a biased drag element mounted in the magnetic field between the magnet and said field-forming device's, one of said fieldforming devices being-comprised in a laminated bi-metallic element whose lamina have different co-efiicients of expansion under change of temperature, whereby the form of said field-forming element ischanged with field between the magnet and the: field plate,

d plate mounted on t e biased dragelement, said the casing meshing with the,

for rotating the i change of temperature to compensate for 1 temperature error inthe readings of the instrument, the 'otherofsaid field-forming devices being mountedfor movement toward and fromthe v mag-net, moving it at will for calibrating the instrument.

6 A speedometer comprising, in combination with a casing, a magnet mounted therein for rotation, and means forrotating it from the shaft whose speed is to be indicated; two field-forming devices composed and means. for so of magnetic metal mounted adjacent to the magnet; a biased dra element positioned in the field between the magnet and said field-forming devices, one of said field-forming devices being comprised in a split ring which encompasses the magnet and which consists of two laminae which have different co-eificients of expansion under change of temperature,whereby the distance of said split ring from the magnet is changed by change of temperature altering its diameter, the other of said field-forming devices being a magnetic plate positioned transversely to the axis of the magnet, said plate being mounted in the casing for movement toward and from the magnet, and means extending outside the case for '50 moving it at will. i

7. A speedometer comprising, in combination with the 'case, a magnet mounted therein for rotation and means for rotating it from the shaft whose speed is to be indicated; a calibrating plate of magnetic material; a threaded support on which it is centrally mounted in a plane tranverse to the axis of rotation of the magnet, and

exteriorly accessible means for rotating the plate on its threaded support to move it toward and from the magnet.

8. A speedometer comprising, in combination with the case, a magnet mounted therein for rotation and means for rotating it from the shaft whose speed is to be indicated; a calibrating plate of magnetic material; a threaded support on which it In testimony hereof I have hereunto set my hand at Chicago, Illinois, this 8th day of January, 1913.

JOHN K. STEWART.

Witnesses:

STANHOPE Hunson, C. B. SMITH. 

